PEX (crosslinked polyethylene) piping is becoming increasingly accepted and specified on commercial plumbing projects because of its flexibility, physical properties and ability to retain the most preferential aspects of metallic piping while improving upon them.
Still, many engineers are hesitant to specify PEX simply because metallic systems have been the norm for so long and often are the default option. However, playing it safe is rarely the ideal option, and a greater understanding of how best to design and size a PEX installation can do much to overcome this hesitation.